1. Technical Field
The present invention relates to (i) a processed substrate which can be used as, for example, a support plate and (ii) a method for manufacturing the processed substrate.
2. Description of the Related Art
It has been desired that a semiconductor chip be processed with microfabrication so that an improvement in each of multifunctionalization of a system, clock frequency, and high-density integration can be further advanced.
Downsizing of the semiconductor chip can be realized by, for example, thinning a wafer which serves as a substrate. However, a thinned wafer noticeably deteriorates in strength, and may have a defect (crack or breakage) due to a subtle contact or heat stress that occurs while the thinned wafer is handled. Thus, the thinned wafer is provided with a processed substrate which is used as, for example, a support plate, such that the thinned wafer is improved in strength while being processed.
Japanese Patent Application Publication, Tokukai, No. 2001-185519 discloses the following invention, which is directed to a technique for a processed substrate. A support substrate (processed substrate) disclosed in JP 2001-185519 includes (i) a support plate having through-holes and (ii) a support plate having no through-hole, and the support plates are combined with each other so as to constitute a two-layer structure. According to the teachings of JP 2001-185519, in a case where the support substrate having the above configuration is used, it is possible to easily remove the support substrate from a wafer after the wafer has been processed.